Intraoperative Electrophysiological Monitoring Research Articles

Application value of intraoperative electrophysiological monitoring in cerebral eloquent area glioma surgery: a retrospective cohort study

IntroductionSurgery for gliomas involving eloquent areas is a very challenging microsurgical procedure. Maximizing both the extent of resection (EOR) and preservation of neurological function have always been the focus of attention. Intraoperative neurophysiological monitoring (IONM) is widely used in this kind of surgery. The purpose of this study was to evaluate the efficacy of IONM in eloquent area glioma surgery.MethodsSixty-eight glioma patients who underwent surgical treatment from 2014 to 2019 were included in this retrospective cohort study, which focused on eloquent areas. Clinical indicators and IONM data were analysed preoperatively, two weeks after surgery, and at the final follow-up. Logistic regression, Cox regression, and Kaplan‒Meier analyses were performed, and nomograms were then established for predicting prognosis. The diagnostic value of the IONM indicator was evaluated by the receiver operating characteristic (ROC) curve.ResultsIONM had no effect on the postoperative outcomes, including EOR, intraoperative bleeding volume, duration of surgery, length of hospital stay, and neurological function status. However, at the three-month follow-up, the percentage of patients who had deteriorated function in the monitored group was significantly lower than that in the unmonitored group (23.3% vs. 52.6%; P < 0.05). Logistic regression analysis showed that IONM was a significant factor in long-term neurological function (OR = 0.23, 95% CI (0.07–0.70). In the survival analysis, long-term neurological deterioration indicated worsened overall survival (OS) and progression-free survival (PFS). A prognostic nomogram was established through Cox regression model analysis, which could predict the probability 3-year survival rate. The concordance index was 0.761 (95% CI 0.734–0.788). The sensitivity and specificity of IONM evoked potential (SSEP and TCeMEP) were 0.875 and 0.909, respectively. In the ROC curve analysis, the area under the curve (AUC) for the SSEP and TCeMEP curves was 0.892 (P < 0.05).ConclusionsThe application of IONM could improve long-term neurological function, which is closely related to prognosis and can be used as an independent prognostic factor. IONM is practical and widely available for predicting postoperative functional deficits in patients with eloquent area glioma.

459 Outcome of Surgeries of Pan Brachial Plexus Injuries - Our 10 Years Experience

INTRODUCTION: Brachial plexus injuries are very much devastating and lead to significant socioeconomic and mental burden to the affected person and his family. In the early days of 20th century many authors were in favour of conservative management even the amputation of affected limb. But in later decades due to development in technological advancement of operating microscope, intraoperative electrophysiological monitoring, biological tissue glue etc. the results of surgical repair are beyond the imagination that could be done previously. METHODS: Our study is a Retrospective observational analytical study in which we included patients of Pan brachial plexus injury operated under the Department of Neurosurgery from April 2011 till February 2023 (excluding covid period from March 2020 to September 2021) at apex trauma center AIIMS Delhi, India. Demographic details, mode of injury, surgery performed and outcome were analyzed. Data was extracted from patient’s casualty, ICU and OT records and analyzed using SPSS version 29.0.0.0. Analysis of outcome was taken in terms of improvement in motor power and quality of life. RESULTS: There were 113 patients diagnosed to have Pan brachial plexus injury by clinical examination and supported with brachial plexus MRI, NCV and EMG of the affected limb. 24 (21.24%) cases underwent Neurolysis only, 17 (15.04%) cases underwent Supraclavicular neurotization only, 24 (21.24%) cases were operated by infraclavicular neurotization and 48 (42.48%) patients were operated by supraclavicular and infraclavicular neurotization both. Respectively 25%, 23.52%, 25% and 35.42% cases had motor and sensory improvement and were able to perform few of their daily activities with lesser support. CONCLUSIONS: In our study at least 25% Patients of Pan brachial plexus injury after surgery got benefited in their routine activity and quality of life thus lesser affected in socioeconomic and psychological front.

Fully endoscopic microvascular decompression for hemifacial spasm: a clinical study and analysis

Fully endoscopic microvascular decompression (MVD) of the facial nerve is the main surgical treatment for hemifacial spasm. However, the technique presents distinct surgical challenges. We retrospectively analyzed prior cases to consolidate surgical insights and assess clinical outcomes. Clinical data from 16 patients with facial nerve spasms treated at the Department of Neurosurgery in the First Affiliated Hospital of Bengbu Medical College, between August 2020 and July 2023, were retrospectively examined. Preoperatively, all patients underwent magnetic resonance angiography to detect any offending blood vessels; ascertain the relationship between offending vessels, facial nerves, and the brainstem; and detect any cerebellopontine angle lesions. Surgery involved endoscopic MVD of the facial nerve using a mini Sigmoid sinus posterior approach. Various operative nuances were summarized and analyzed, and clinical efficacy, including postoperative complications and the extent of relief from facial paralysis, was evaluated. Fully endoscopic MVD was completed in all patients, with the offending vessels identified and adequately padded during surgery. The offending vessels were anterior inferior cerebellar artery in 12 cases (75%), vertebral artery in 3 cases (18.75%), and posterior inferior cerebellar artery in 1 case (6.25%). Intraoperative electrophysiological monitoring revealed that the lateral spread response of the facial nerve vanished in 15 cases and remained unchanged in 1 case. Postoperative facial spasms were promptly alleviated in 15 cases (93.75%) and delayed in 1 case (6.25%). Two cases of postoperative complications were recorded—one intracranial infection and one case of tinnitus—both were resolved or mitigated with treatment. All patients were subject to follow-up, with no instances of recurrence or mortality. Fully endoscopic MVD of the facial nerve is safe and effective. Proficiency in endoscopy and surgical skills are vital for performing this procedure.

Modified Selective Dorsal Rhizotomy Exposure Method for Adults With Spastic Paralysis of the Lower Limbs.

Spinal deformities are a common complication after selective dorsal rhizotomy (SDR). In this article, we introduce a more minimally invasive SDR procedure in adult patients with spastic paralysis of the lower limbs. In this retrospective analysis of SDR in 8 adult patients with spastic paralysis of the lower limbs, a modified exposure method was used during the surgery. Only the lower part of the L1 spinous process, upper part of the L2 spinous process, and part of the lamina were resected through L1-2 interlaminar approaches. The motor and sensory roots were found to be completely dependent on electrophysiological monitoring. The sensory roots of the target muscle groups were partially transected. All patients were followed up for 2-4 years. The degree of lower extremity spasm was assessed using the Gross Motor Function Classification Scale, Ashworth grading, Gross Motor Function Measure-66, joint range of motion, and electromyography analysis. All 8 patients were successfully operated with the help of intraoperative electrophysiological monitoring. The Ashworth score of the target muscles, Gross Motor Function Measure-66 score, and range of motion of the joints improved significantly after surgery. Two patients achieved cross-grade improvement in their Gross Motor Function Classification Scale scores. No persistent incision pain or spinal deformities were observed during follow-up. The interspinous process approach provides sufficient surgical space and reduced the damage to the bone structure of the spine. The electrophysiological monitoring protocol is suitable for adult patients with lower extremity spasm.

Outcome predictors in a series of 40 patients after surgery for low-grade gliomas

ObjectiveLow grade gliomas (LGGs) account for 15 % of primary brain tumors. The paper has the aim to identifying prognostic factors affecting overall survival (OS) and progression-free survival (PFS), and to evaluate the outcome of patients. MethodsA total of 40 patients undergoing surgery for cerebral LGG (WHO grades I and II) at Our Institute were enrolled in the retrospective study. Inclusion criteria were: histological diagnosis of LGG, availability of complete clinical-instrumental documentation and follow-up data. For each patient, the following were analyzed: the clinical parameters in the preoperative and postoperative phases, the histological variant of the tumor, the extent of surgical resection (EOR) and any use of intraoperative methods, the Mib-1/Ki-67 proliferation index, the administration of adjuvant chemotherapy and/or radiotherapy and the occurrence of any complications. ResultsThe cohort included 14 males and 26 females. The independent predictors of OS at multivariate analysis were: age, pre-operative KPS, Ki67/Mib-1, EOR and adjuvant chemotherapy. With regard to PFS, statistical significance on multivariate analysis was observed for pre-operative KPS, Ki67/Mib-1, EOR, post-operative tumor volume and radiotherapy. An EOR < 80 % was confirmed as negative prognostic factor for both OS and PFS. Lastly, the pre-operative tumor volume and the use of Intra-operative Electrophysiological Monitoring were significantly associated with EOR. ConclusionIn this study, according to the literature, several prognostic factors determining the outcome of LGG patients, both in terms of OS and PFS, were confirmed. Knowing the impact of these parameters in terms of prognosis would guide the choice of treatment, which will necessarily be multidisciplinary and tailored.

Positioning of epidural electrode for motor cortex stimulation in general anesthesia based on intraoperative electrophysiological monitoring to treat refractory trigeminal neuropathic pain

BackgroundMotor cortex stimulation (MCS) represents a treatment option for refractory trigeminal neuralgia (TGN). Usually, patients need to be awake during surgery to confirm a correct position of the epidural electrode above the motor cortex, reducing patient’s comfort.MethodEpidural cortical mapping (ECM) and motor evoked potentials (MEPs) were intraoperatively performed for correct localization of motor cortex under general anesthesia that provided comparable results to test stimulation after letting the patient to be awake during the operation.ConclusionIntraoperative ECM and MEPs facilitate a confirmation of correct MCS-electrode position above the motor cortex allowing the MCS-procedure to be performed under general anesthesia.

The application of electrophysiology in the correction of spastic torticollis by triple surgery—report of 96 cases

ObjectiveTo investigate the effect and value of electrophysiology in the ‘triple operation’ (selective excision of spastic muscles in the neck, selective resection of the posterior branch of the cervical nerve and accessory neurotomy) of spastic torticollis.MethodsPreoperative electromyography (EMG) examination was performed on 96 patients with spastic torticollis treated in our hospital from January 2015 to December 2019. The results were used to assess the responsible muscles’ primary or secondary position and the function of antagonistic muscles and to formulate a personalised surgical plan. A Cascade PRO 16-channel electrophysiological diagnostic system (produced by Cadwell, USA) was used to record the evoked EMG. Target muscles were denervated under intraoperative electrophysiological monitoring and re-examined by EMG six months later to evaluate the efficacy.ResultsThe satisfactory rate of target muscle denervation was 95%, and the overall good rate was 79.1%.ConclusionElectrophysiological examination and intraoperative application may have a positive value in the selection of the operative method, improving the rate of denervation and evaluating the prognosis of the ‘triple operation’.

Intraoperative Cortico-Cortical Evoked Potential

In the surgery management of lesions in areas of the eloquent cortices the preservation of brain functions is required. Intraoperative electrophysiological methods are necessary to preserve the integrity of the functional network, such as motor or language areas. Cortico-cortical evoked potentials(CCEPs)have recently developed as a new intraoperative monitoring method because of advantages of a recording time of approximately 1-2 min, no requirement of patient cooperation, and high reproducibility and reliability of the data. The recent intraoperative CCEP studies have shown that CCEP can map the eloquent areas and white matter pathway, such as the dorsal language pathway, frontal aslant tract, supplementary motor area, and optic radiation. To establish intraoperative electrophysiological monitoring even under general anesthesia, further studies are required.

Analysis of the effect of neuroendoscopy-assisted microscopy in the treatment of Large (Koos grade IV) vestibular schwannoma.

This article aimed to investigate the effects of the endoscopic-assisted microsurgery technique on the resection of large (Koos grade IV) vestibular schwannoma (VS) and provide a prognosis analysis of the patients. A retrospective analysis of the use of the endoscopic-assisted microsurgery technique in 16 cases of large vestibular schwannoma surgery was carried out. Intraoperative nerve electrophysiological monitoring was conducted to explore the effect of neuroendoscopy on the resection of internal auditory canal tumors, protection of the facial nerve, and minimizing postoperative complications. Tumors were completely removed in all 16 cases, and the facial nerve was anatomically preserved in 14 cases (87.5%). There was no postoperative cerebrospinal fluid leakage and no intracranial infection complications occurred.Following the House-Brackmann (H-B) grading system, post-operative facial nerve function was grade I in 5 cases, grade II in 6 cases, grade III in 3 cases, and grade V in 2 cases. As a result, the preservation rate of facial nerve function (H-B grade I-II) was 68.8%. All 16 patients were followed up for 3 to 24 months, and no tumor recurrence was found on enhanced MRI. Using the endoscopic-assisted microsurgery technique in the retrosigmoid approach has many advantages over the microscopic-only approach. When compared to the microscopy-only approach, the endoscope can provide a wide-angle surgical field superior to that of a microscope in areas such as the internal auditory canal in the resection of large VS, minimize iatrogenic injuries, ensure complete removal of internal auditory canal tumors, and well as reducing postoperative complications such as cerebrospinal fluid leakage and the loss of facial and auditory nerve functions.

Chinese expert consensus on intraoperative neurophysiological monitoring of intracranial aneurysms (2023 edition)

Intracranial aneurysm is a common disease in neurosurgery, and intraoperative vascular injury causes postoperative ischemic complications that seriously influence patient prognosis. Intraoperative neurophysiological monitoring (IONM) enables effective identification of early intraoperative ischemia and thus reduces related complications. The Clinical Neurophysiology Committee of the Chinese Research Hospital Association and the Neurosurgeons Branch of the Chinese Medical Doctor Association organized national experts in neurophysiology and cerebrovascular disease to develop this expert consensus based on a review of published guidelines, consensuses and clinical evidence both at home and abroad, and after Delphi expert consultation. A consensus was formed on four aspects, including commonly used IONM techniques and parameter settings, perioperative preparation and interpretation of results, the value of intraoperative electrophysiological monitoring of aneurysms at different sites, and electrophysiological monitoring in special cases. Moreover, according to level of evidence recommended by GRADE criteria, nine recommendations were put forward from the above four aspects to provide a reference for clinical intracranial aneurysm intraoperative neurophysiological monitoring practice.

Interdisciplinary surgical approach enables complete tumor resection with preservation of neurological function in specific conditions of pediatric solid malignancies

PurposeSuccess of pediatric solid tumor surgery is regularly hampered by infiltration of essential neurovascular structures. A surgical dilemma arises when imaging data suggest a conflict between complete resection and preservation of neurological function. The aim of the study was to analyze data of children harboring tumors with involvement of neurovascular structure treated by an interdisciplinary pediatric surgical/neurosurgical team.MethodsWe retrospectively analyzed data of 25 children undergoing surgery for solid tumors, in whom preoperative imaging showed a relevant involvement of nerve structures. Surgery was simultaneously performed by a pediatric onco-surgeon and a pediatric neurosurgeon with peripheral nerve expertise, including intraoperative electrophysiological monitoring.ResultsThe following tumors were treated: NF1 associated neurofibromas (10), neuroblastomas (5), desmoid tumors (2), MPNST (2), ganglioneuroma (1), Ewing sarcoma (1), infantile fibromatosis (1), PNET (1), rhabdomyosarcoma (1), angiolipoma (1). The most frequent tumor localizations were the pelvis (n = 7) and retroperitoneal region (n = 6). Median age at surgery was 8 years (1.5–16). Macroscopically complete tumor resection was achieved in 24/25 patients. In 2/4 patients with limb tumors an amputation was planned externally. In both, a limb-salvage procedure was possible. Transient postoperative neurological deficits occurred in 2/25 patients. Four patients had tumor relapses. All but one are alive after a median follow-up of 46 months (2–155).ConclusionsSimultaneous interdisciplinary pediatric surgical/neurosurgical approach enables radical tumor resection with preservation of neurological function in patients suffering from solid tumors with involvement of relevant neurovascular structures. This approach should be performed by experienced surgeons in reference pediatric onco-surgical centers.

Predictive Value of Transimpedance Matrix Measurements to Detect Electrode Tip Foldover.

To evaluate the ability of the transimpedance matrix (TIM) measurement to detect cochlear implant electrode tip foldover by comparing results to a "gold standard," the intraoperative plain film radiograph. Retrospective case series. Tertiary referral hospital. One hundred three patients who underwent cochlear implantation between June 2020 and August 2021. Intraoperative electrophysiologic monitoring (electrode impedances, neural response telemetry, and TIM measurement) and modified Stenver's view plain film radiographs. Identification of tip foldover on both TIM and plain films. In total, 103 patients (117 ears) had both a TIM measurement and intraoperative X-ray available for review, including 68 adults and 35 children. One hundred patients (85%) received the Cochlear Slim Modiolar electrode. Tip foldovers were noted in three of 117 implants (2.5%). In all cases, TIM was able to detect the foldover, and the electrode arrays were reinserted with the patients still under anesthesia, with repeat X-ray demonstrating a normal configuration. Two other abnormal TIM patterns were identified. One was in a patient with an obstructed cochlea in whom only 10 electrodes could be inserted, the other was in a patient with a common cavity abnormality. One additional patient underwent electrode repositioning intraoperatively because of overinsertion. In this patient, the TIM appeared to be within normal limits, but the over-insertion was apparent on X-ray. Overall, the sensitivity and specificity of TIM measurements in detecting electrode tip foldover were both 100%. TIM measurements were able to accurately identify tip foldovers. More research is needed to define the adjunctive role of TIM as an intraoperative measure.

Not Just an Anchor: The Human Filum Terminale Contains Stretch Sensitive and Nociceptive Nerve Endings and Responds to Electrical Stimulation With Paraspinal Muscle Activation.

BACKGROUND:Neural components of the fibrous filum terminale (FT) are well known but are considered as embryonic remnants without functionality.OBJECTIVE:To investigate the ultrastructure of human FT specimens for sensory nerve endings and record paraspinal muscle activity on electrostimulation of the FT.METHODS:We prospectively investigated a cohort of 53 patients who underwent excision of the FT for the treatment of tethered cord syndrome. Surgical FT specimens were investigated by light and transmission electron microscopy. Intraoperative electrophysiological routine monitoring was extended by recording paraspinal muscles above and below the laminotomy level.RESULTS:Light microscopy revealed tiny peripheral nerves piercing the pia mater of the FT and entering its fibrous core. Transmission electron microscopy unveiled within the fibrous core of the FT myelinated nerve structures in 8 of the 53 patients and unmyelinated ones in 10 of the 53 patients. Both nerve endings encapsulated in fibrous tissue or unencapsulated nonmyelinated Schwann cell nerve bundles, that is, Remak cells, were found. Those nerve endings resembled mechanoreceptor and nociceptive receptor structures found in human skin, muscle tendons, and skeletal ligaments. Specifically, we found Ruffini mechanoreceptors and in addition nerve endings which resembled nociceptive glioneural structures of the skin. Bipolar electrostimulation of the FT was associated with paraspinal muscle activity above and below the spinal segment at which the FT was stimulated.CONCLUSION:Morphological and electrophysiological results indicate the presence of functional sensory nerve endings in the FT. Like other spine ligaments, the FT may serve as a proprioceptive element but may also contribute to back pain in spine disorders.

Surgical treatment of solitare brain metastases

Background. Brain metastasis occurs in 10–30 % of patients with different malignances. Despite of successes, achieved in the treatment of extracranial malignances in last decade, tendency to increase of the survival and duration of the disease-free period in patients with brain metastasis is absent. Several treatment modalities: chemotherapy, radiation, immune and target therapy, stereotactic radiosurgery, different types of surgical procedures, however, an optimal combination of these methods remain unclear.The aim of the study: to summarize experience of complex treatment of patients with brain metastases in hospital with opportunity of both surgical removal, chemo- and radiotherapy and review literature on the topic.Materials and methods. The retrospective analysis of medical data of patients with brain metastases performed with assessment of most frequent sources of metastases, there value, localization, median survival duration from metastasis revealing due to different types of therapy, main period of recurrences and hospital state duration, early and late complications. Inclusion criteria were: patients with surgical treatment of brain metastases, availability of medical data. Exclusion criteria were: multiple brain metastases, contraindications for surgical treatment, sensitive to chemo- and radiation therapy malignances (leukoses, lymphoma, germinative tumors etc.). The assessment of degree of metastasis resection was made by postop CT and MRI with intravenous enhancement or by operation records. Intraoperative florescence was used for evaluation of tumor borders. In case of localization of metastasis in sensory or motor zones intraoperative electrophysiological monitoring acquired. Few operations for metastasis localized in speech zones were made with «asleep–awake–asleep» method. Follow-up assessed by questioning of patients and their relatives. Statistical analyzes performed in IBM SPSS Statistics 23.Results. 52 patients meet criteria and were included to the study. Male to female ratio was 1 : 1, main age – 60 years. The most common sources of brain metastases were (in decreasing order) melanoma, lung cancer, kidney cancer, breast cancer, rectal cancer, prostate cancer, ovarian cancer and uterus cancer. Two patients had 2 brain metastases at the time of assessment, other 50 – single. Most common localizations of brain metastases (in decreasing order) were: parietal lobe, frontal lobe, cerebellum hemispheres, occipital lobe, temporal lobe, ventricular system and brain meninges. In 46 % of cases metastases involves significant functional areas of brain. Median value of metastasis was 11 cm3; midline dislocation appeared in 65,4 % of cases; 6 patients have hemorrhage in the tumor, 2 – seizures, 2 – occlusive hydrocephalus. Main Karnofsky performance index – 73,8. Total resection performed in 84,6, subtotal resection – in 7,7 % of cases gross. Intraoperative fluorescence used in 73 %. In 10 cases metastasis localized in motor and sensory zones, all these cases were treat with intraoperative neurophysiological monitoring. Postoperative hemiparesis noticed in 1 patient; 3 surgeries performed with awake; no aphasias mentioned. Follow-up was assessed in 44 patients, 20 of them were dead at the time of the study. An assessment of dependence of overall survival median on primary tumor morphology performed. Prognostic factors of brain metastases: its morphology and value, extent of resection, Karnofsky status and early complications.Conclusions. Most patients with brain metastasis are in satisfactory condition. Most frequent tumors which form brain metastasis: melanoma and lung cancer, they are characterized by poorer prognosis. Most metastasis are supratentorial, intracranial hypertension is obvious. Metastasis localization, time from its evaluation to surgery, significant functional areas involvement and primary tumor resection aren’t fluent on survival.

Intramedullary Spinal Cord Lesions: A Single-Center Experience.

ObjectiveSpinal cord tumors constitute a small part of spinal surgery owing to their rarity. This retrospective study describes their current management. MethodsForty-eight patients were treated for an intramedullary tumor between 2014 and 2020 at a single institution. Patients’ files were retrospectively studied. We detailed clinical status according to neurological deficit and ambulatory ability using the modified McCormick Scale, radiological features like number of levels, associated syringomyelia, surgical technique with or without intraoperative electrophysiological monitoring, pathological findings, and postoperative outcome. ResultsThe median age of this population was 43 years, including 5 patients under 18 years. The median delay before first neurosurgical contact was 3 months after the first clinical complaint. Treatment was gross total resection in 43.8%, subtotal resection in 50.0%, and biopsy in 6.2%. A laminectomy was performed for all the patients except 2 operated using the laminoplasty technique. Pathological findings were ependymoma in 43.8%, hemangioblastoma in 20.8%, and pilocytic astrocytoma in 10.4%. Six patients were reoperated for a tumor recurrence less than 2 years after the first surgical resection. One patient was reoperated for a postoperative cervical kyphosis. ConclusionIntramedullary tumors are still a challenging disease and they are treated by various surgical techniques. They must be managed in a specialized center including a trained surgical, radiological, electrophysiological, and pathological team. Arthrodesis must be discussed before performing extensive laminectomy to avoid postoperative kyphosis.

Reconstruction clipping of ruptured anterior circulation aneurysms via supraorbital lateral keyhole approach

BackgroundIntracranial aneurysm (IA) is a serious disease. Analyze and review the cases of anterior circulation ruptured IA by supraorbital lateral keyhole approach, and summarize the experiences of this approach.MethodsRetrospective analysis of 16 cases of ruptured anterior circulation IA in our department from January 2019 to June 2020, CT angiography (CTA) was performed before operation. Analyzing the IA’s parameters by 3D-CT reconstruction. The IA was clipped by supraorbital lateral keyhole approach combined with the 3D-skull reconstruction. Extraventricular drainage was performed before craniotomy. Intraoperative neurophysiological monitoring was performed during the operation. After operation, fluorescein angiography and vascular ultrasound were performed to check the clipping effect. Intracranial pressure monitor was performed postoperatively. CTA was reexamined one week after operation. The modified Rankin Scale (MRS) was performed 6 months after operation.ResultsThere were 7 males (43.8%) and 9 females (56.2%), and the average age is 52.31 ± 11.12 years old. Among them, 11 patients (68.8%) were anterior communicating artery aneurysms and 5 (31.2%) were middle cerebral artery aneurysms. All patients were out of hospital within 10 days without any death, without cerebral infarction, cerebrospinal fluid leakage and neurological impairments. About mRS score, after 6 months follow-up, 8 cases (50%) had 0 point, 4 cases (25%) had 1 point, and 4 cases (25%) had 2 points.ConclusionsFor ruptured anterior circulation IA, the supraorbital lateral keyhole approach combined with ventricular drainage, intraoperative electrophysiological monitoring, and intraoperative vascular ultrasound is a safe and minimally invasive treatment. The application of reconstruction clipping can reconstruct the diameter of parent vessel and reduce the recurrence rate of IA.

Surgical treatment of hemispheric and subcortical gliomas adjacent to corticospinal tract in children using MR tractography and intraoperative electrophysiological monitoring

Difficult total resection of supratentorial gliomas adjacent to the corticospinal tract (CST) is due to the high risk of its injury and disability of patients. The main methods for preventing intraoperative CST damage are preoperative MR tractography and intraoperative electrophysiological monitoring. The problem of total resection of gliomas adjacent to the CST with preservation of high functional status is difficult due to immaturity and plasticity of brain structures in children. Moreover, the advantages of MR tractography combined with intraoperative monitoring have not been described. The authors present surgical treatment of supratentorial gliomas adjacent to the CST at different anatomical levels. Patients underwent preoperative and postoperative MR tractography and intraoperative electrophysiological monitoring. MR tractography provided preoperative data on CST lesion. Intraoperative monitoring made it possible to identify and preserve CST in the depth of surgical wound. MR tractography and intraoperative electrophysiological monitoring increase resection quality in patients with hemispheric and subcortical gliomas without postoperative functional deterioration.

Novel microscope-based visual display and nasopharyngeal registration for auditory brainstem implantation: a feasibility study in an ex vivo model

PurposeAn auditory brainstem implant (ABI) represents an alternative for patients with profound hearing loss who are constrained from receiving a cochlear implant. The positioning of the ABI electrode influences the patient’s auditory capacity and, therefore, quality of life and is challenging even with available intraoperative electrophysiological monitoring. This work aims to provide and assess the feasibility of visual-spatial assistance for ABI positioning.MethodsThe pose of the forceps instrument that grasps the electrode was electromagnetically navigated and interactively projected in the eyepieces of a surgical microscope with respect to a target point. Intraoperative navigation was established with an experimental technique for automated nasopharyngeal patient registration. Two ABI procedures were completed in a human specimen head.ResultsAn intraoperative usability study demonstrated lower localization error when using the proposed visual display versus standard cross-sectional views. The postoperative evaluations of the preclinical study showed that the center of the electrode was misplaced to the planned position by 1.58 mm and 3.16 mm for the left and the right ear procedure, respectively.ConclusionThe results indicate the potential to enhance intraoperative feedback during ABI positioning with the presented system. Further improvements consider estimating the pose of the electrode itself to allow for better orientation during placement.

Evaluation of Functional Outcome Following Resection of Supratentorial Lesions at Eloquent Brain Areas

Abstract Objectives Microsurgical management of intrinsic brain tumors aims to maximize the extent of resection and to minimize the postoperative morbidity. The purpose of this study is to evaluate the functional outcome following surgical excision of supratentorial lesions at eloquent brain areas such as language, motor and sensory cortex, regarding the extent of resection, the karnofsky performance scale, the neurological deficit and seizure control. Methods A prospective study of 25 patients aged 15-55 years, 15 females and 10 males underwent surgical excision of supra-tentorial lesions at eloquent brain, The Karnofsky Performance Score (KPS), seizure attacks and neurological deficits were analyzed before and after resection. Functional resection was implemented using preoperative functional magnetic resonance image (fMRI), intraoperative image guidance and electrophysiological monitoring under total intravenous anesthesia (TIVA) or awake craniotomy and the extent of resection was quantified postoperatively. Results Preoperative median KPS was 76.8%. It improved one year post-operatively to 89.2%. One patient died 3 weeks postoperatively due to neurological, cardiac and chest complications. The pathology report revealed recurrent metastatic adenocarcinoma GIII. Preoperatively, twenty-three patients had seizure attacks, 10 were controlled and 13 were uncontrolled on medication. Postoperatively seven patients were Engels classification IC and 17 patients were controlled on anti-epileptics (Engels classification ID). Preoperatively 19 patients had hemiparesis/ hemiplegia, while immediate (one week) postoperatively 13 patients improved, 8 patients experienced initial worsening of the preoperative deficits and 4 patients had the same deficit as preoperatively while at 1-year postoperatively, 24 patients improved. Gross total resection (&amp;gt;95%) was achieved in 19 patients, subtotal resection (&amp;gt;75%) in 4 patients and partial resection (&amp;gt;65%) in 2 patients. Conclusion Functional resection is believed to be a key prognostic factor in supratentorial lesions at eloquent brain regarding improving of karnofsky performance scale, neurological outcome and seizure control.

Surgery of the Brainstem

The book “Surgery of the brainstem” is a richly illustrated book, covering almost every aspect of surgery in and around the brainstem. The first two sections (Chapters 1–4) of the book cover the history of brainstem surgery and the complex anatomy. Section III (Chapters 5–7) deals with the neurologic examination of patients with brainstem pathology, imaging, and intraoperative electrophysiologic monitoring. Surgical approaches to the brainstem, thalamus, and pineal region are explained in great detail in Section IV (Chapters 8–12). Section V (Chapters 13–22) deals with the management of tumors, whereas Section VI (Chapters 23–32) deals with the management of vascular pathologies in and around the brainstem. In the last section with the heading “Implants and cranial nerve repair,” the role of auditory brainstem implants in treating hearing loss is discussed.